Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Adhesive outermost layer
Reexamination Certificate
2001-09-17
2003-05-06
Seidleck, James J. (Department: 1711)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Adhesive outermost layer
C428S3550RA, C428S356000, C428S3550RA, C524S009000, C524S047000, C523S105000, C523S111000, C523S120000
Reexamination Certificate
active
06558792
ABSTRACT:
This is a nationalization of PCT/DK00/00129, filed March 17, and published in English. This application is to be prosecuted on the basis of originally filed Chapter I claims.
FIELD OF THE INVENTION
The present invention relates to pressure sensitive adhesive compositions suitable for various medical applications and especially suitable for use for adhesion to the skin, in particular in the field of ostomy care. More specifically, this invention relates to adhesive compositions comprising a rubbery elastomeric base and two or more water soluble or water swellable hydrocolloids are dispersed therein, the use of such adhesive compositions for the preparation of a wound dressing or an adhesive wafer for an ostomy appliance, and to wound dressings or ostomy appliances comprising such adhesive composition and a mixture of hydrocolloids.
BACKGROUND OF THE INVENTION
In connection with surgery for a number of diseases in the gastrointestinal tract a consequence is, in many cases, that the colon, the ileum or the urethra has been exposed surgically and the patient is left with an abdominal stoma and the effluents or waste products of the body, which are conveyed through these organs, are discharged through the artificial orifice or opening and are collected in a collection bag, which is usually adhered to the skin by means of an adhesive wafer or plate having an inlet opening for accommodating the stoma. Also in connection with a fistula, the patient will have to rely on an appliance to collect the bodily material emerging from such opening.
In connection with treatment of wounds, it is often desirable to cover and protect the wound with a skin barrier or dressing comprising a backing and an adhesive layer for contacting the wound and the surroundings for ensuring a bacteria-tight closure of the wound.
Various skin adhesive agents are used today for the above mentioned purposes.
Such adhesives should have a composition which is sufficiently tacky to secure the appliance or skin barrier to the abdomen, and a cohesion ensuring safe removal thereof without leaving residues on the skin. Furthermore, the adhesive should show a degree of elasticity to enable the adhesive layer of the appliance or barrier to follow the movements of the patient without slipping the skin and should also show a great resistance to erosion caused by aggressive exudates from an ostomy in order to minimise the risk of leakage. Still further, no adverse reactions or effects should be inflicted upon the user from using the adhesives.
A very widespread embodiment of skin adhesive agents comprises a self-adhesive elastomeric matrix, in which water-absorbing, swelling particles, the so-called hydrocolloids, are dispersed.
Adhesive compositions comprising hydrocolloids have been known for many years. U.S. Pat. No. 3,339,549 discloses a blend of a rubbery elastomer such as polyisobutylene and one or more water soluble or water swellable hydrocolloids such as a powdery mixture of pectin, gelatine and carboxymethylcellulose. The adhesive mass has a water-insoluble film applied to one surface. A composition of this type is available commercially from E. R. Squibb & Sons Inc. under the trademark “Stomahesive” and is used as a skin barrier around stomas to prevent skin breakdown by the corrosive fluids discharged by the stoma.
In adhesive compositions of this type, the polyisobutylene is responsible for provision of the adhesive properties and the dispersed hydrocolloid powders absorb fluid and render the adhesive agent capable of also adhering to moist skin (wet tack). These compositions are also gaining increasing acceptance as wound dressings for dermal ulcers, burns and other exuding wounds.
WO 97/30093 (Hercules Incorporated) discloses polyvalent cation crosslinked pectin fibre composition composed of a calcium sensitive methoxyl pectin with a degree of esterification of less than 15% or calcium sensitive amidated pectin having a degree of esterification of less than 50% where the pectin is polyvalent cation crosslinkable and has an average molecular weight having an upper limit of 200,000 and a lower limit of 5000. The fibres are stated to be useful in making of wound dressings as a part of a gauze material. One major problem which has been encountered with conventional adhesive compositions comprising hydrocolloids is their susceptibility to breakdown upon exposure to body fluids. When the compositions are used as skin barriers, e.g., around stomas, absorption of fluid is desirable, but excessive swelling causes the composition to lose its integrity opening for leaks and the barrier must be replaced more often than is desirable from a skin protection point of view, and very often, a residue remains on the skin, which in many cases is difficulty to remove. Furthermore, an increased awareness has developed with respect to avoiding constituents which could be a potential risk of transferring infectious diseases using material of animal origin.
A number of attempts have been made to improve the integrity of adhesive compositions.
As a method for improving the adhesive integrity the use of hydrocolloids has been described which, in themselves, are cross-linked (e.g. cross-linked carboxymethylcellulose (CMC), cross-linked dextran and other water-absorbing, but insoluble hydrocolloids). They will not dissolve due to the cross-linked structure. During the swelling process the individual particles will, therefore, obtaining a gel-like structure, but no coherent gel could be formed since the macromolecules of the cross-linked hydrocolloids are locked in the gel network constituted by the individual particles. Due to the lack of a coherent gel, the cross-linked hydrocolloids may be leached out and suspended in the body fluids and the effect on the integrity of the swelled adhesive, therefore, is limited.
Generally speaking, these prior methods improve the integrity of adhesive compositions. Nevertheless, a need still exists for an improved adhesive composition showing resistance to biological fluids as well as improved properties of adhesion to the skin.
Now it has been found that it is possible to provide an improved adhesive composition showing at least as good resistance to biological fluids as well as adhesion to the skin and integrity in the form of improved coherence as state of the art adhesives without having to rely on material of animal origin, especially gelatine.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a pressure sensitive adhesive composition suitable for various medical applications and especially suitable for use for adhesion to the skin, in particular in the field of ostomy care, which adhesive composition comprises a rubbery elastomeric base and two or more water soluble or water swellable hydrocolloids dispersed therein.
Furthermore, the invention relates to ostomy appliances comprising such adhesive compositions and the use of such adhesive compositions for preparing wound dressings or ostomy appliances.
Still further, the invention relates to a mixture of hydrocolloids suitable for inclusion in pressure sensitive skin-friendly adhesives.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a pressure sensitive adhesive composition suitable for medical purposes comprising a rubbery elastomeric base and two or more water soluble or water swellable hydrocolloids, said adhesive composition comprising a substantially homogeneous mixture of 15-60% of one or more rubbery components, 20-60% of a mixture of hydrocolloids comprising one or more hydrocolloids selected from the group of amidated pectins and potato starch, 0-50% of one or more tackifier resins, 0-10% of a plasticizer and 0-5% pigment.
By introducing a combination of hydrocolloids particles comprising amidated pectin and/or potato starch, constituents of animal origin are avoided, and at least as good integrity of the hydrocolloid adhesive and gel integrity are achieved together with a good cohesion and absorption of water as compared with the state of the art adhesives comprising gelatine. Thus, a very commonly
Ciok Danuta
Vaabengaard Rikke
Coloplast A/S
Jacobson & Holman PLLC
Ribar Travis B
Seidleck James J.
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